1. Field of the Invention
The present invention relates to a hot air welder that consecutively joins sheets of synthetic resin material together to make a large-sized pavilion or a tent fabric, or welds and seals the seam lines of waterproof textiles or the like for waterproofing process, and particularly to a hot air welder that operates upper and lower drive rollers having different fixed-positions and shapes according to the patterns and sizes or shapes of fabrics to be welded with hot air, and selects drive rollers in a suitable state for the work fabric, thereby making the welding process easier, greatly reducing the defective ratio of the welding process and increasing the productivity.
2. Description of the Related Art
As shown in FIG. 6, a conventional hot air welder includes upper and lower rollers on a table-shaped body 100, and a separately-provided hot air generator 101 between the upper and lower rollers. When overlapped sheets of synthetic resin and a film supplied from a weld film portion 102 are introduced between the upper and lower rollers, the hot air generator 101 discharges a hot air thereto, so that the overlapped synthetic resin sheets are heat-welded by high temperature heat in combination with the compression operation of the upper and lower rollers.
Besides the welding process, the hot air welder is also used in a waterproofing process for seam lines of waterproof products, where a separately provided waterproof film is heat-welded for the seam lines of the waterproof products, thereby ensuring their complete waterproof protection.
Thus-welded sheet fabrics are used in a case where it is impossible to make a large-sized sheet fabric at a time, like the pavilion or a large-sized tent fabric. In addition, for clothes requiring the waterproof protection, like a raincoat or special working clothes, the synthetic resin film is heat-weld for the seam line of its fabric, thereby manufacturing waterproof fabrics having much improved waterproof ability.
However, in the above-mentioned conventional hot air welder, because the welding means is disposed on the table-shaped body, the table-shaped body serves as a barrier to the work and causes troubles in securing the workspace, making the work difficult. In addition, in a case of performing a waterproofing process for clothes such as waterproof clothes, it is very difficult or impossible to perform the waterproofing process for the seams of sleeve or shoulder parts.
Further, when various welding angles or positions are needed along the seam lines, as in the waterproofing work for the waterproof clothes having various to-be-welded parts, the conventional hot air welder cannot meet the requirement, failing to perform the waterproofing work for the seam lines, because the drive roller for conveying the introduced sheet is fastened on the table-shaped body.
Therefore, it is an object of the present invention to overcome the above-mentioned problems of the prior art, and the object is achieved by providing a hot air welder for synthetic resin wherein, instead of the conventional table-shaped body, there are provided an upright-standing drive body; hot-air welding means on an upper-side of the drive body; upper and lower drive rollers under the welding means, and wherein the welding work is performed by rotating and using alternatively the upper drive roller or the lower drive roller, according to the kind of fabrics to be welded and the work-substances, so that the heat welding and waterproofing process may be performed more easily for more various shaped work-substances, and that the troublesome work-substances such as sleeve or shoulder parts of waterproof clothes that have various positioned and shaped seam lines may be moved and rotated easily by the worker to be heat-welded and become waterproofed.